<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<script type="text/javascript">
		var a = 12;
		alert(typeof (a));

		var str = "hello world";
		alert(typeof(str));

		var b = false;
		alert(typeof(b));
	</script>

</body>
</html>